El método takeFirst() de BlockingDeque devuelve y elimina el primer elemento del contenedor Deque, esperando si es necesario hasta que un elemento esté disponible. El método lanza una InterruptedException si se interrumpe mientras espera.
Sintaxis:
public E takeFirst()
Devoluciones: este método devuelve el primer elemento del contenedor Deque, esperando si es necesario hasta que un elemento esté disponible.
Excepción : la función lanza una InterruptedException si se interrumpe mientras espera.
Nota : El método takeFirst() de BlockingDeque se ha heredado de la clase LinkedBlockingDeque en Java.
Los siguientes programas ilustran el método takeFirst() de LinkedBlockingDeque:
Programa 1:
// Java Program to demonstrate takeFirst()
// method of BlockingDeque
import java.util.concurrent.BlockingDeque;
import java.util.concurrent.BlockingDeque;
import java.util.*;
public class GFG {
public static void main(String[] args)
throws InterruptedException
{
// create object of BlockingDeque
BlockingDeque<Integer> BD
= new LinkedBlockingDeque<Integer>();
// Add numbers to end of BlockingDeque
BD.add(7855642);
BD.add(35658786);
BD.add(5278367);
BD.add(74381793);
// print Deque
System.out.println("Blocking Deque: " + BD);
// removes the front element and prints it
System.out.println("Head of Blocking Deque: "
+ BD.takeFirst());
// prints the Deque
System.out.println("Blocking Deque: " + BD);
}
}
Blocking Deque: [7855642, 35658786, 5278367, 74381793] Head of Linked Deque: 7855642 Blocking Deque: [35658786, 5278367, 74381793]
Programa 2: Para demostrar InterruptedException
// Java Program to demonstrate takeFirst()
// method of BlockingDeque
import java.util.concurrent.LinkedBlockingDeque;
import java.util.concurrent.BlockingDeque;
import java.util.*;
public class GFG {
public static void main(String[] args)
throws InterruptedException
{
// create object of BlockingDeque
BlockingDeque<Integer> BD
= new LinkedBlockingDeque<Integer>();
// Add numbers to end of BlockingDeque
BD.add(7855642);
BD.add(35658786);
BD.add(5278367);
BD.add(74381793);
// print Dequeue
System.out.println("Blocking Deque: " + BD);
BD.clear();
// throws error as the list is empty and it
// is interrupted while waiting
System.out.println("Head of Blocking Deque: "
+ BD.takeFirst());
}
}
Errores de tiempo de ejecución:
Max real time limit exceeded due to either by heavy load on server or by using sleep function
Referencia: https://docs.oracle.com/javase/7/docs/api/java/util/concurrent/BlockingDeque.html#takeFirst()